The present invention relates to hand tools for forming a metal sheet, and more particularly, to a hand tool for bending a metal sheet along an edge to form a flange of a desired width.
Hand tools that are commonly used to bend a metal sheet to form a flange either engage the metal sheet to form a flange of a fixed width or require marking or scoring of the metal sheet to provide a guide for bending the flange. An example of the former is disclosed by U.S. Pat. No. 3,848,454 to Hall. Hall discloses a four sided tool having a bending slot on each side. Opposed bending plates are separated by a centrally positioned spacer plate that is smaller than the bending plates. The bending plates define the slots by extending from the spacer plate to edges at different distances from the spacer plate. The spacer plate forms the inner boundary of the slot. Flanges of two widths, equal to the distances from the spacer plate to the edges of the bending plates, may be formed by each bending slot by pivoting the tool about the edge of one of the bending plates. An example of a tool that requires marking of the metal sheet is disclosed by U.S. Pat. No. 4,934,175 to Hensler et al. Hensler et al. discloses a bending tool having spaced apart right angle members positioning parallel surfaces to form a slot. The metal sheet is positioned between the spaced apart surfaces at a desired location. A lever is mounted to the tool and a force is applied to the lever to rotate the tool bending the metal sheet.
A bending tool manufactured by Malco Products Co., Inc. provides two bending slots of different fixed depths and has openings into the bending slots. The tool is formed by two identically sized rectangular plates that are secured to each other. The plates are formed to diverge from each other at a selected distance from a side and a second selected distance along an opposed side. The plates extend in parallel spaced apart relation from the diverging location forming two bending slots of different depths along the opposed edges of the tool. Two openings extend through the plates at spaced apart locations along each bending slot. Straight sections of each opening boundary diverge continuously from a location at a selected distance from the edge of the plate to the location that the plates diverge to form the bending slot.
Neither type of bending tool is well suited to forming a flange at an edge of a metal sheet being is formed to closely overlie an irregular or irregularly sized surface. Aluminum sheet overlying facia, window trim, or door trim are examples of formed metal sheet that must be bent at various distances from an edge of a metal sheet Additionally, aluminum facia, window trim, and door trim must often be formed by hand in relatively inaccessible locations. Flanges of different widths and lengths are required and are most conveniently formed by a hand tool when the metal sheet is positioned adjacent to the surface it is being formed to overlie.
Conventional bending tools cannot form a flange within a range of widths without having to mark the metal sheet or determining the width of the flange in order to select an appropriate tool.